Audio
A good rule of thumb is that PDF does not allow for text-to-speech conversion while HTML does, depending upon the publisher/vendor making that feature available to the user.
Audiobook websites, not affiliated with Magale Library
http://www.openculture.com/freeaudiobooks
http://www.learnoutloud.com/Free-Audio-Video/Literature/World-Classics
Databases with audio component (Not all articles in all databases have this feature.)
EBSCOhost databases-Click on the Listen link when you retrieve an article.
NAXOS Music Library-Classical music recordings. Our subscription allows for 15 simultaneous users.
Ebook Collections by Title:
Credo Reference Click on the speaker icon at the top of your article’s/result’s page.
Gale Virtual Reference Library Click on the Listen link on the page your result is on.